Intelligent automated assistants (or digital assistants) integrated in natural-language processing systems can provide a beneficial interface between human users and electronic devices. Such assistants can allow users to interact with devices or systems using natural language in spoken and/or text forms. For example, a user can provide a speech input containing a user request to a digital assistant operating on an electronic device. The digital assistant can interpret the user's intent from the speech input and operationalize the user's intent into tasks. The tasks can then be performed by executing one or more services of the electronic device, and a relevant output responsive to the user request can be returned to the user. In some examples, however, natural-language processing systems, particularly those including intelligent automated assistants, require extensive training to properly implement machine learning and are computationally demanding.